Introduction: The efficacy of combined modality treatment (CMT) with chemotherapy (CT) and radiotherapy (RT) in early-stage Hodgkin Lymphoma (eHL) is offset by long-term morbidity, with a cumulative incidence of Second Primary Malignancy (SPM) at 40 years of 48.5% (Schaapveld 2015). The primary endpoint of the RAFTING trial is a 3-Y PFS >/= 90% of a RT-free CT (2 or 4 ABVD cycles) in low-risk non-bulky stage I-IIA eHL with a low Metabolic Tumor Volume at baseline (bMTV) and a negative PET-2. Secondary endpoints: (a) Effectiveness of delayed Involved-node RT (In-RT) and Nivolumab maintenance, 240 mg. i.v. twice a month for one year (Nivo-m) in case of “limited” relapse (LR: stage I-II with up to 3 new nodal areas) after CT; (b) effectiveness of the triplet: ABVD x 4, InRT and Nivo-m in high-risk eHL, with either a high bMTV or a positive PET-2; (c) predictive value of tumor cell-free DNA (cfDNA) in detecting an impending relapse during follow-up of patients (p.) in CR after CT alone.
Methods: RAFTING is a prospective phase 2 multi-center, international trial, enrolling 160 non-bulky stage I-IIA eHL p. from four European countries. Treatment intensity is tailored to three classes of p. with a different risk of treatment failure, depending on (a) the modified EORTC criteria (m-EORTC), in which classical bulky is taken over by a Large Nodal Mass (LNM, defined by the largest diameter > 5 cm in CT or PET/CT scans), (b) bMTV and (c) PET-2. The risk-stratified treatment is the following: Group 1: PET-2 neg. & low bMTV p, treated with 2-4 ABVD cycles (depending on m-EORTC), addressed, once in CR, to a 3-monthly cfDNA assay; Group 2: group 1 p. relapsing with a LR, treated with delayed INRT at the dose of 36 Gy, and Nivo-m; Group 3: PET-2 positive (Group 3a), and/or a high bMTV (Group 3b) p. treated with ABVD x 4, INRT, (20 or 30 Gy), and Nivo-m. All PET/CT are centrally reviewed.
Results: out of 55 p. enrolled 52 were eligible, and 31/52 with both bMTV and PET-2 assessed were stratified for risk as follows: group 1a: 6; group 1b 17; group 3a: 2; Group 3b: 6. Three p. of group 3 are on Nivo-m, without major side effects. Updated results will be presented.
Conclusions: (a) the majority of p. enrolled so far (74%) belong to Group 1 (low risk), and most of them (74%) are treated with 4 ABVD because of mEORTC criteria (most often a LNM) ; (b) Most p. were attributed to Group 3 because of a high bMTV (6/8); (c) Nivo-m is feasible, safe and well-tolerated (no SAE).
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